The present invention relates to a casting vessel for hotchamber pressure diecasting machines, which vessel is cast in one piece from heat-resistant tool steel, and, more particularly, to a casting vessel which comprises a casting chamber with running surfaces for a casting plunger, and an ascending bore arranged approximately in parallel to the casting chamber so as to lead into the casting chamber at one end and equipped at the other end with a mouthpiece for connecting a nozzle.
In a known casting vessel of the type shown in DE-AS 21 43 937, the ascending bore is cast in with inserted cores. For this purpose, the ascending bore extends axially out of the casting vessel at one end and is closed by a screw applied there. The connection to the casting chamber takes place by way of a duct extending perpendicularly to the casting chamber which was also formed by an inserted core and must also be closed off to the outside by a screw. The machining of the ascending bore and as well as of the transverse duct therefore requires relatively high expenditures. This also applies to the connecting cone for the nozzle provided in the area of the mouthpiece. As a result of the rectangular transition from the connecting duct to the ascending bore and of the approximately rectangular transition provided also in the area of the mouthpiece, pressure losses occur for the flowing molten bath which may have a disadvantageous effect on the working speed.
It is an object of the present invention to provide such a casting vessel in which pressure losses are avoided and no high expenditure machining operations are required.
The foregoing object has been achieved in accordance with the present invention by providing a cast-in pipe as an ascending bore in such a casting vessel. This pipe is bent in the area of the mouth leading to the casting chamber and in the area of the mouthpiece and is welded together from at least two parts. As a result, it is now possible to cause the transition into the parallel part of the ascending pipe by means of a fluidically advantageous deflection. As a result of the welded construction of the pipe, it is also now possible to vary the geometry of the pipe and to adapt the pipe in each particular case to the loads to be expected for the deflection of the molten bath as well as to the stresses to be expected as a result of the occurring temperatures.
According to another advantageous feature of the present invention, the ascending pipe comprises a first elbow in the area of the mouth leading to the casting chamber, an essentially straight pipe piece which connects to this first elbow and a second elbow in the area of the mouthpiece which connects to the pipe piece. As a result of this construction, both elbows may be individually adapted to the respective requirements without the necessity of taking into account the dimensions of the straight pipe piece disposed between them.
The second elbow may advantageously also consist of a piece having a receiving cone for the nozzle so that there will not be any problems with respect to intersecting points. The wall thickness of the receiving cone may increase in the direction of the opening so that the wall thickness meets the demands of the occurring stress at the critical point. Furthermore, the inside diameters of the elbows can be changed and reduced in the flowing direction of the molten bath so that an adaptation to the specific fluidic requirements becomes possible. It is also possible to vary the bending radii and to construct the wall thicknesses of the elbow parts to differ and to adapt them to the respective existing conditions.